Jargon is like special vocabulary of a say hobby, for instance, that a certain group of that hobby would only understand.
For Example: Instead of language, we have jargon: instead of principles, slogans: and, instead of genuine ideas, bright ideas
Slang is a more informal language. Teenagers better understand slang. It's like the language of teenagers.
For Example: For police officers, they have five-o, for marijuana, they have bud etc....